> Copyright law does not protect ideas, methods, or systems. Copyright protection is therefore not available for ideas or procedures for doing, making, or building things; scientific or technical methods or discoveries; business operations or procedures; mathematical principles; formulas or algorithms; or any other concept, process, or method of operation.
https://www.copyright.gov/comp3/chap300/ch300-copyrightable-...
> 313.3(A) Ideas, Procedures, Processes, Systems, Methods of Operation, Concepts, Principles, or Discoveries
> Section 102(b) of the Copyright Act expressly excludes copyright protection for “any idea, procedure, process, system, method of operation, concept, principle, or discovery, regardless of the form in which it is described, explained, illustrated, or embodied in such work.” 17 U.S.C. § 102(b); see also 37 C.F.R. § 202.1(b). As such, any work or portion of a work that is an idea, procedure, process, system, method of operation, concept, principle, or discovery does not constitute copyrightable subject matter and cannot be registered.
> ...
> Mathematical principles, formulas, algorithms, or equations.
You can copyright creative expressions that use math formulas, but only that expression itself would be covered. E.g. a paper presenting a proof of a theorem would be copyrightable, but all of the facts expressed by the formulas would not be copyrightable.